The majority of prior art nail trimmers are mechanically constructed and include two opposed blades. The nail is inserted between the blades and a lever handle is depressed, forcing the blades together and thereby slicing through the nail. However, while these mechanical clippers are seemingly easy to operate, problems can arise which would make the utilization of these clippers difficult.
Various medical conditions, such as fungus growth or merely the normal aging process can cause thickening of the toenails. This is especially true for the nail on the great toe or hallux. This thickening makes it very difficult or impossible to insert the nail between the opposed blades of the mechanical clipper. Additionally, even if the nail can be properly inserted, other conditions, such as arthritis or neuritis which might be present in conjunction with the thickened or ingrown nail, would prevent the user from applying sufficient pressure to the lever handle to sever the nail, or cause pain and tissue damage to the user. Therefore, an electrically powered vibratory nail trimmer which would be simple to use by elderly people would be quite advantageous.
A number of U.S. patents such as U.S. Pat. Nos. 2,544,248 issued to Ashmead; 2,597,526 issued to Kessler; 3,081,782 issued to Funk; 3,596,667 issued to Buercklin; 4,016,890 issued to Fiorenza, Sr. et al.; and 4,177,854 issued to Rosenbloom relate to electrically powered manicuring devices. However, these patents are primarily used to buff fingernails, not to cut or trim the nails.
U.S. Pat. No. 2,131,628, issued to Kohl, describes a hand-held electric vibrating mechanism used for nail care. However, as was true with the above-cited patents, this patent is directed to manicuring, but not the cutting of the nail.
U.S. Pat. No. 3,554,197, issued to Dobbie, describes a portable powered saw which utilizes a blade oscillating about the center of a circle. An electric motor produces rotary motion which is converted into oscillatory motion at the blade. This patent includes an oscillating pivot arm unit using an extended convex blade protruding horizontally from the end of the tool, whereby oscillation is performed by a motor driven spring attached to the blade mounting. This patent is used to cut bones during surgery and would be difficult to be adapted to use as a nail trimmer.
Other U.S. patents of interest include U.S. Pat. Nos. 2,336,017 issued to Fortune; 2,427,580 issued to Stryker; and 3,533,161 issued to Magnin. These patents describe devices used for cutting plaster casts which cannot easily be used to trim nails.